📈 Percentage Change

Calculate increases and decreases using percentages

🎯 What You'll Learn

Calculate percentage increase and decrease
Use the percentage change formula correctly
Distinguish between increase and decrease
Solve real-world percentage change problems

✏️ Explanation

Percentage change shows how much a quantity has increased or decreased compared to its original value.

Percentage Change = (Change ÷ Original) × 100

Where Change = New Value - Original Value

🔍 Why It Matters

Essential for understanding price changes, growth rates, discounts, and statistics in news and business. Percentage change helps compare how much things have grown or shrunk over time.

🧭 Percentage Change Calculator

Follow this 4-step process to calculate percentage change:

Find the Change

25 - 20 = 5

→

Divide by Original

5 ÷ 20 = 0.25

→

Multiply by 100

0.25 × 100 = 25%

→

Check Direction

25% increase

Change → Divide → Multiply → Direction

✏️ Worked Example: £20 to £25

Given: A price increases from £20 to £25. What's the percentage increase?

Step 1: Find the change

Change = £25 - £20 = £5

Step 2: Divide by original value

£5 ÷ £20 = 0.25

Step 3: Convert to percentage

0.25 × 100 = 25%

Answer: 25% increase

🧮 Percentage Change Calculator

Calculate percentage change:

From to =

Find the change

Change = 100 - 80 = 20

Divide by original value

20 ÷ 80 = 0.25

Convert to percentage

0.25 × 100 = 25% increase

Percentage Change:

25%

From 80 to 100 is a 25% increase

🔢 Practice Exercises

1. Price drops from £80 to £60. Find percentage decrease.

2. Population grows from 5000 to 5500. Find percentage increase.

3. A shirt was £30, now £24. What's the percentage decrease?

4. Sales increase from 200 to 250 units. Find percentage change.

5. Temperature drops from 15°C to 12°C. Find percentage decrease.

⚠️ Common Mistakes

Using new value instead of original value in the denominator
Forgetting to multiply by 100 to get the percentage
Confusing increase with decrease - check if the change is positive or negative

✨ Quick Summary

Percentage change = (Change ÷ Original) × 100. Check if it's increase or decrease.